1. Field of the Invention
The present invention relates to an air-conditioning apparatus and, more particularly, to an air-conditioning apparatus having an oxygen ratio increasing device.
2. Description of the Related Art
In recent years, an air-conditioning apparatus with an oxygen content increasing device has been developed. The oxygen content increasing device is arranged in an indoor unit of the air-conditioning apparatus to produce oxygen from carbon dioxide in indoor air. The produced oxygen is supplied to indoor air to increase an oxygen concentration of the indoor air. The oxygen content increasing device comprises a water tank arranged in the indoor unit and containing water in which a special catalyst is dissolved, a sunbeam receiving unit arranged outdoors, and optical fibers for transmitting sunbeams received by the sunbeam receiving unit to the indoor unit. The sunbeams guided by the optical fibers are emitted on the water tank, and carbon dioxide is blown in the water tank. An organic compound and oxygen are produced by photosynthesis.
However, the content of carbon dioxide in indoor air is generally small. In an oxygen content increasing device for producing oxygen by photosynthesis from this carbon dioxide, oxygen production efficiency is low, and the oxygen concentration of the indoor air cannot be efficiently increased. In nighttime or a cloudy day, when sunbeams cannot be sufficiently received, photosynthesis cannot be performed. As a result, it is impossible to produce oxygen. In addition, since the oxygen content increasing device is arranged in the indoor unit of the air-conditioning apparatus, the indoor unit becomes bulky. A large space for the indoor unit is required, and the installation location is also limited.